How should I correct this sentence? I am writing a formal article. Microsoft Word shows that the sentence below is grammatically wrong and change "can" into "cans". I don't think it's right but I don't know how should I correct this? Thanks~ "The first of these projects was an intelligent traffic light that—in addition to its basic functions as a traffic signal—can also show time, temperature, and humidity as well as count vehicles. "

Are these three sentences grammatically correct? If these sentences are not correct how should I correct these? (1) I hope this letter can facilitate your knowing more about her. (2) I quickly convinced Jack’s high level of persistence. (3) I appreciate the importance both personally and professional of her continued education, the highest loud.

What's the meaning of "dial it down a notch" ?